<!DOCTYPE html>
<html lang="en">
<head>
	<meta charset="UTF-8">
	<title>Document</title>
	<script src="https://cdn.bootcss.com/vue/2.6.10/vue.js"></script>
	<link href="https://cdn.bootcss.com/animate.css/3.7.2/animate.css" rel="stylesheet">
	<style>
		.v-enter,.v-leave-to{
			opacity: 0;
		}
		.v-enter-active,.v-leave-active{
			transition: opacity 1s;
		}
	</style>
</head>
<body>
	<div id="root">
		<transition-group>
			<div v-for="item of list" :key="item.id">
				{{item.title}}
			</div>
		</transition-group>	
		<button @click="handleBtnClick">ADD</button>
	</div>
	<script type="text/javascript">	
		var count=0;
		var vm=new Vue({
			el:"#root",
			data:{
				list:[]
			},
			methods:{
				handleBtnClick:function(){
					this.list.push({
						id:++count,
						title:'hi'
					})
				}
			}
		})
	
	</script>
</body>
</html>